I am currently using JpaSort
with Spring Data commons 1.9.1 and Spring JPA 1.7.1. I need to use QueryDSL because JPA does not allow defining the sort for null values.
This is my Repository
public interface DatasheetRepository extends JpaRepository<Datasheet, Long>, JpaSpecificationExecutor<Datasheet>
I am doing this in my Controller:
Page<Datasheet> page = m_datasheetRepository.findAll( new PageRequest( pageNumber, pageSize, createSortForDatasheets() ) );
This is what I had with JPA:
private Sort createSortForDatasheets()
{
// First sort on the component type name, then on the subtype name
return new JpaSort( JpaSort.path( Datasheet_.componentSubtype ).dot( ComponentSubtype_.componentType ).dot( ComponentType_.name ) )
.and( new JpaSort( JpaSort.path( Datasheet_.componentSubtype ).dot( ComponentSubtype_.name ) ) );
}
This is what I have changed it to for QueryDSL:
private Sort createSortForDatasheets()
{
return new QSort( new OrderSpecifier<>( Order.ASC, QDatasheet.datasheet.componentSubtype.componentType.name,OrderSpecifier.NullHandling.NullsLast ) )
.and( new OrderSpecifier<>( Order.ASC, QDatasheet.datasheet.componentSubtype.name, OrderSpecifier.NullHandling.NullsLast ) );
}
However, nothing seems to get sorted. I have enabled DEBUG logging and I see this:
Rendered criteria query -> select generatedAlias0 from Datasheet as generatedAlias0 order by generatedAlias0.name asc, generatedAlias0.name asc
If I change it to:
private Sort createSortForDatasheets()
{
return new QSort(QDatasheet.datasheet.name.desc());
}
Then the sorting by the name of my "Datasheet" type in reverse order does work.
This is my "Datasheet" entity:
@Entity
public class Datasheet
{
// ------------------------------ FIELDS ------------------------------
@Id
@GeneratedValue
private long id;
@Column(unique = true)
private String name;
private String description;
@ManyToOne
private ComponentSubtype componentSubtype;
@OneToMany(cascade = CascadeType.REMOVE)
private Set<DatasheetDocument> documents;
And this is "ComponentSubtype":
@Entity
public class ComponentSubtype
{
@Id
@GeneratedValue()
private long id;
private String name;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "parent_id",insertable=false,updatable=false)
private ComponentType componentType;
UPDATE:
If I change the createSortForDatasheets
to this:
private Sort createSortForDatasheets()
{
return new QSort( new OrderSpecifier<>( Order.ASC, QComponentType.componentType.id, OrderSpecifier.NullHandling.NullsLast ) );
}
Then, the logging shows:
Rendered criteria query -> select generatedAlias0 from Datasheet as generatedAlias0 order by generatedAlias0.id asc
Notice how the id of the "Datasheet" is used, and not the id of "ComponentType".
It looks like Spring Data bug. I filed an issue for it https://jira.spring.io/browse/DATACMNS-621